(Fixed) [HOU-1285] 32 bit output on renderchannels

[LeoYfver]

We would like to be able to force 32 bit output on some renderchannels. For example extraTex and zdepth

Regards Alexis

[Gosho.Genchev]

Hello,

have you guys tried setting the Images -> Image Format -> Bits per Channel option to 32 bit ? I just tested with the View Metadata node in Nuke and it seems the channel is proper 32bit float.

[LeoYfver]

problem is we have so many renderchannels and dont want to render 32 bit on everything. Maya has this forced 32 bit output on the extraTex renderchannel.

[Gosho.Genchev]

I've just added this toggle in the UI, the devs will need to hook things up tomorrow and you should be good to go.

Note that it seems the toggle only has an effect when rendering to multi-channel EXRs (single EXR file for all elements). To do so, you would need to remove the ${AOV} tag from the output path. It also appears that Z-Depth should be forced to 32 bit output regardless of bit depth settings.

Hope that helps!

[LeoYfver]

Perfect! Thanks

[psanitra]

Gosho.Genchev What about situation where each AOVt has it`s own EXR file? Can we have that properly saved with 16/32 bit too? there are only couple of passes that really need 32float...

[Gosho.Genchev]

Hey, Peter,

developers say it's possible but in general, using Multi-Channel EXRs is preferable (where forcing 16-bit is already possible). For instance, vector values are stored as actual vectors in Multi-Channel EXRs but fitted zero to one to be represented as colors when rendering Single-Channel.

Is there is a particular reason you prefer to render single-channel files ?

Cheers!

[psanitra]

There are many good reasons for having and option to same single channels sequences.

- big file, can be and issue many times, specially when rendering on external render farms,and sending output to clients on last minute. As example i had shots this year, that had 200-400GB per camera/render, roghly 20 AOVs in one multichannel EXR. When grabing such a render from farm, it`s preferable to just download beauty first, and then the rest. For quick check, or for sending it to client quicker, so it can go to edit, to pre-comp etc. So it makes a different between, downloading and uploading to client 20GB of data or 300GB.

-from all clients i ever worked with, nobody ever asked for multichannel exr. Instead when talking about outputs, everybody will send you what their naming conventions are for each pass It`s just more common that people are using file sequence per AOV. It`s easier to transfer,process and remove. Not everybody is on latest Nuke. For example when i work for "print", people will ask for separate file as mask, or extra specular. From user view, it`s just easier to grab a file from the folder, then having to use extra tools to extract mask from multichannel exr. Or to install extra plugins for Photoshop or running your command line VRimg converter.

-clean up, archiving - I tend to clean up a project a bit after i`m done and place it into archives. Removing what is not necessary to reopen the project later. Usually i delete the passes that were not used, and just keep those used in comp. That`s not possible when everything is in multichannel EXRs. i Have to keep everything, or delete everything.

Right now with single channels exr not saving bit depths properly, I have to run around folders and convert passes to f16bit before sending to client

[docaml]

Everything psanitra said is correct!

[Gosho.Genchev]

Thank you, psanitra and docaml ,

I'll relay the info to the dev team - hopefully a solution can be found. I'll keep you posted with any updates.

Again, thanks, this really helps!

[Gosho.Genchev]

Hello,

the core team has added support for forcing 32 bit output for 16-bit single channel EXRs. The elements which support this are the Extra Texture and Z-Depth. Z-Depth will always be exported to 32-bit while for Extra Texture (and custom AOVs from the Material Output VOP), you'll have to manually specify this using the "Force 32-bit Output" toggle.

This should soon be available across all integrations.

Cheers!